The distance to the surface of the water in a well can sometimes be found by dropping an object into the well and measuring the time elapsed until a sound is heard If t is the time in seconds it takes for the object to strike the water then t obeys the equation s 16t where s is the distance in feet Solving for t we have t 5 4 Let to be the time it takes for the sound of the impact to reach your ears Since sound waves travel at a speed of approximately 1100 feet per second the time to travel the distance s is t s 1100 Now t t is the total time that elapses from the moment that the object is dropped to the moment that a sound is heard We have the equation 5 Total elapsed time t t 1 4 S 1100 Falling object 5 Sound waves S 1100 Find the distance to the water s surface if the time elapsed from dropping a rock to hearing water is 7 0 seconds S feet Round to the nearest hundredth as needed